He should have also said, take your car somewhere to get the OBD scanned for codes. CEL on = you will find a code that will tell you which system is messed up. Auto parts stores often scan it for free.
The wrench light Throttle Control/Transmission:
Illuminates when a powertrain fault has been detected. Contact your authorized dealer as soon as possible.
While Service Engine Soon says:
The Service engine soon indicator light illuminates when the ignition is first turned to the on position to check the bulb and to indicate whether the vehicle is ready for Inspection/Maintenance (I/M) testing. Normally, the “Service engine soon” light will stay on until the engine is cranked, then turn itself off if no malfunctions are present. However, if after 15 seconds the “Service engine soon” light blinks eight times, it means that the vehicle is not ready for I/M testing. See the Readiness for Inspection/Maintenance (I/M) testing in the Maintenance and Specifications chapter.
Solid illumination after the engine is started indicates the On Board Diagnostics System (OBD-II) has detected a malfunction. Refer to On board diagnostics (OBD-II) in the Maintenance and Specifications chapter. If the light is blinking, engine misfire is occurring which could damage your catalytic converter. Drive in a moderate fashion (avoid heavy acceleration and deceleration) and have your vehicle serviced immediately by your authorized dealer.
In view of this I'm not really sure what OBD code to expect from a wrench light.